Hi there,
To do this you would need to use the netflow capability of Prime. Configure your WLCs as netflow exporters and use Prime as the collector/ analyser.
Last time I used Prime (v3.1) for this feature, I found it to be slow with confusing filtering which produced frankly unusable results, requiring us to export the raw netflow data and filter it ourselves. You are better off using alternative netflow collectors/ analysers.
cheers,
Seb.